# Tönnis — Tönnis grading of hip osteoarthritis

> Grades hip osteoarthritis radiographically.

**Situação:** vigente · **Órgão:** Musculoesquelético · **Órgão emissor:** Orthopedic consensus · **Versão:** 1976 · **Ano:** 1976

## Procedência e vigência
- Família: léxico
- Tipo de lógica: flat
- Modalidade: XR
- Fonte primária: Tönnis D. Normal values of the hip joint for the evaluation of X-rays (Tönnis) (1976) — https://en.wikipedia.org/wiki/T%C3%B6nnis_classification
- Última verificação: 2026-06-26
- Última checagem: 2026-06-26

## Categorias

| Código | Rótulo | Critérios | Conduta | Risco | Localizador | Verificado |
| --- | --- | --- | --- | --- | --- | --- |
| 0 | Grade 0 | No radiographic signs of osteoarthritis: no subchondral sclerosis, normal joint space, no subchondral cysts, and a normally spherical femoral head. | Favorable for joint-preserving surgery: the literature supports hip preservation (arthroscopy/FAI correction, osteotomy) for Tonnis 0-1 hips, with the most predictable outcomes. | Best prognosis for hip preservation; lowest reported conversion to total hip arthroplasty after arthroscopy. | Tonnis grade definitions from open-access PMC7391593 (binary Tonnis modification), Table 1 (grade 0 = no OA); preservation-for-0/1 principle from the same article ('hip preservation for hips graded Tonnis 0 and 1, replacement for 2 and 3'). | ✓ |
| 1 | Grade 1 | Mild osteoarthritis: increased subchondral sclerosis with minimal joint-space narrowing and early osteophyte formation; the femoral head contour remains essentially normal. | Still suitable for joint-preserving surgery: arthroscopy/FAI surgery in selected patients shows durable improvement, though slightly less reliable than grade 0. | Good prognosis: outcomes after hip preservation are generally predictable in Tonnis 0-1. | Tonnis grade definitions from open-access PMC7391593, Table 1 (grade 1 = sclerosis, minimal JSN, osteophytes); preservation suitability for Tonnis 0-1 from the same article. | ✓ |
| 2 | Grade 2 | Moderate osteoarthritis: small subchondral cyst formation with moderate joint-space narrowing and moderate loss of femoral-head sphericity. | Gray zone: joint preservation/arthroscopy has only a limited, selective role with clinical equipoise; many favor caution because conversion to arthroplasty is markedly more likely. | Worse prognosis than grade 1: Tonnis 2 at baseline carries a significantly higher risk of conversion to total hip arthroplasty (about 3.4-fold relative to Tonnis 1), with 10-year arthroscopy survivorship ~38% vs ~81% for grade 1. | Grade-2 definition from open-access PMC7391593, Table 1 (small cysts, moderate JSN); THA conversion RR 3.44 (95% CI 1.81-6.55) and 10-yr survivorship 38% vs 81% from open-access PMC12205409 (Nikou et al., 10-year hip-arthroscopy outcomes). | ✓ |
| 3 | Grade 3 | Severe (advanced) osteoarthritis: large subchondral cysts, severe joint-space narrowing or obliteration, and severe deformation of the femoral head. | Total hip arthroplasty is the realistic treatment: hip-preservation/arthroscopy is generally not recommended at this stage of advanced degeneration. | Poorest prognosis for preservation: hip-preserving procedures are rarely durable, and arthroplasty is the reliable option. | Grade-3 definition from open-access PMC7391593, Table 1 (large cysts, joint-space obliteration, severe head deformation); replacement-rather-than-preservation for Tonnis 2-3 stated in the same article. | ✓ |

### Citações por categoria
- **0**: Tönnis D. Normal values of the hip joint for the evaluation of X-rays (Tönnis) (1976) — https://en.wikipedia.org/wiki/T%C3%B6nnis_classification · Tonnis grade definitions from open-access PMC7391593 (binary Tonnis modification), Table 1 (grade 0 = no OA); preservation-for-0/1 principle from the same article ('hip preservation for hips graded Tonnis 0 and 1, replacement for 2 and 3').
- **1**: Tönnis D. Normal values of the hip joint for the evaluation of X-rays (Tönnis) (1976) — https://en.wikipedia.org/wiki/T%C3%B6nnis_classification · Tonnis grade definitions from open-access PMC7391593, Table 1 (grade 1 = sclerosis, minimal JSN, osteophytes); preservation suitability for Tonnis 0-1 from the same article.
- **2**: Tönnis D. Normal values of the hip joint for the evaluation of X-rays (Tönnis) (1976) — https://en.wikipedia.org/wiki/T%C3%B6nnis_classification · Grade-2 definition from open-access PMC7391593, Table 1 (small cysts, moderate JSN); THA conversion RR 3.44 (95% CI 1.81-6.55) and 10-yr survivorship 38% vs 81% from open-access PMC12205409 (Nikou et al., 10-year hip-arthroscopy outcomes).
- **3**: Tönnis D. Normal values of the hip joint for the evaluation of X-rays (Tönnis) (1976) — https://en.wikipedia.org/wiki/T%C3%B6nnis_classification · Grade-3 definition from open-access PMC7391593, Table 1 (large cysts, joint-space obliteration, severe head deformation); replacement-rather-than-preservation for Tonnis 2-3 stated in the same article.


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> Conteúdo de referência reescrito. Confira a publicação primária vigente. Não é dispositivo médico nem substitui o julgamento clínico. O radiologista responsável pelo laudo permanece o autor e o responsável.

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